An architect uses a computer program to design a skateboard ramp. The function f(x)=ax^2 represents the shape of the ramp's cross section. A portion of the design is shown. On the ramp, a person can skateboard from point A through point B and over to point C. If point C is the same distance above the x-axis as point B, what are its coordinates? Explain. Assume that each grid line represents one unit, with the intersection of the x- and y-axes being the point (0,0).